Trench tamper



Feb. 7, 1939,

F. W. WEBER TRENCH TAMPER Filed Feb. 24, 1937 5 Sheets-Sheet l y M W F.

Feb. 7,4 1939.I F' w WEBER Y 2,146,101

vTRENGH TAMPER Filed Feb, 24, 1957 S'Sheets-Sheet 2 28 2' Flai. 5.

Feb. 7, 1939,

F. W. WEBER 2,146,101

' TRENCH TAMPER Filed Feb, 24, 1937 3 Sheets-Sheet 5 Invenor. F.' W.Weber By MIJ, ai mw H orneys.

Patented Feb. 7, 1939 UNITED STATES PATENT OFFEQE TRENCH TAMPER Calif.

Application February 24, 1937, Serial No. 127,411

7 Claims.

My. invention relates to a machine for tamping earth in back lls intrenches or the like. In a great deal of pipe conduit and similarinstallation work it is necessary to excavate extensive and sometimeslengthy trenches and then back iill the earth into the trench. Where thetrench is in a roadway or similar ground surface used extensively, it isnecessary that the back iill have the same. density of consolidation asthe neigh- 10 boring portion of the ground so that when for instancearoad is re-paved that there will be no cracking or settlement at thetrench. Also in trench excavation through open countries such as elds,it is also advisable to compact the earth when reiilled in the trench inorder that it will be unnecessary to leave an elongated pile on top ofthe trench to take care of natural settlement or that there will be nosettlementbelow the ground surface. Frequently in trench constructionand installation particularly of large pipes after the back iillit isnecessary to remove the surplus earth. Before doing this it is necessaryforl the contractor or builder of the installation to be assured thatthe trench is adequately re- -11d and tamped. Otherwise after removingthe surplus earth a settlement may develop along the length of thetrench requiring a back haul of earth to lill in ,the settlement in thetrench to bring the level up with that of the adjacent -V ground orroad-bed.

A common practice in trench reiilling to assure the proper density andsettlement of the back lill` is by hand tamping, which is an inefcientand expensive procedure. Sometimes this is done by flooding `the trenchwith water and allowing settlement by the water seeping downwardly inthe soil. This latter however is objectionable in that it does not givea uniform settlement-and consolidation of the soil in the trench andfrequently where the ground adjacent a trench lacks suflicient porositythe water does not settle out of .the material in the trench in asuiciently short length of time. The hand tamping is also frequentlycombined with wetting of the material rellled into the' trench toconsolidate this both by the hand tamping and partial water settlementbut this likewise is ineiiicientand expensive.

An object of my invention is the development of a machine which willeiiiciently tamp the earth Lreiilled ina trench and assure a density ofthe soilA refilled at least equal .to that of the adjacent soil. Forthis purpose I have made an adaptation vof a machine known in the tradeas a "sheeps foot which type of machines are fre- 5"-:Vquently'usedk ongrading work, extensive earth lls for dams and the like. The typicalsheeps foot machine employs a drum from which a number of legs extendradially, these terminating at their end in feet or shoes. drum is towedover ground surface to be com- 5 pacted, the feet or shoes penetrate thesoil, ea'ch foot thrusting a` small section of the soil downwardly. Thedrums have such a large number of these legs with feet or shoes and suchare arranged in such a staggered manner on the drum 10 that the wholemass of the soil over which the sheeps foot is operated is compacted. Inthis operation it is usual to dampen the soil.

However the ordinary sheeps foot machine is .V not suitable for trenchwork. Therefore my in- 15 vention includes a special construction andmounting for the sheeps foot drum so that this may be towedlongitudinally for instance in a deep trench gradually approaching thesurface Y after the refill is completed and the towing is done 20 by a.truck or the like driven on the ground surface parallel to the edge ofthe trench. In this construction it is necessary therefore to provide anelongated frame having side beams, the frame being of substantially thewidth of the trench and 25' the side beams being constructed quite thinas to horizontal section so that the sheeps foot drum may be as large aspossible to effect the tamping the full width of the trench. It is alsonecessary y to have a forward guide structure formed inte- 30 gral withthe frame to prevent the drum skewing anglewise to the trench andtherefore tending to bind against one side of the trench wall. Myinvention provides for this in the frame by having the forwardfportioncontracted in a gradual 35 manner and by providing a sliding shoeextending rearwardly from the forward portion of the frame. This alsohas a spreader plate which distributes the material dumped in the trenchevenly across the bottom of the trench so that the drum 40 with .thepenetrating legs and feet may have aneven bed of loose soil on which tooperate.

My invention also includes a tow bar construction. This is madetelescopic to accommodate trenches of different depths and to beshortened 45 if desired as the trench becomes filled. The forward end ofthe tow bar is connected by a swivel moving on a vertical pivot forconnection to a towing truck and the rear end of the tow bar has apivoting connection to the forward 'contracted 50 end of the frame, thispivot being horizontal. Another detailed feature involves the connectionof the tow bar and frame to a truck in which the swivel at the forwardend of the tow bar is preferably made with a transverse tube which kTherefore when the y the parallel side beams I3 at theconverginganglemay be slipped over a pipe secured to the truck and extendinglaterally from one side of the truck across the trench. In addition aguiding cable or chain is connected from the frame to the forwardportion of the truck and forms a diagonalk with the accompanyingdrawings, in which:

Fig. 1 is a plan taken in the direction of the arrow I of Fig. 2illustrating the assembly of a. towing truck with my trench tamperindicated as proceeding in a trench in one direction.

Fig. 2 is a side elevation taken in the direction of the arrow 2 of Fig.l showing the side of the trench adjacent the truck and operating overmaterial loosely dumped in the trench.

Fig. 3 is a partial elevation showing the trench tamper on a return runin the trench.

Fig. 4 is ay vertical transverse section on the line 4 4 of Fig. 1 inthe direction ofthe arrows showing the manner of the spreader blade andsheeps foot drum operating on material dumped into the trench.

Fig. 5 is a plan of the tamper taken in the direction of the arrow 5 ofFig. 6, a portion of the tow bar being omitted. f f

Fig. 6 is a side elevation taken in the direction of the arrow 6 of Fig.5, also showing a portion of the tow bar omitted.

Fig. 7 is a plan of the tow bar taken in the direction of the arrow 1 ofFig. 8.

Fig.8 is a side elevation partly broken away of f the tow bar taken inthe direction of the arrow 8 of Fig. 7.

Fig. 9 is a horizontal rsection on the line 9-9 of Fig. 6 through aportion of the tamper to illustrate mainly the drum and the mounting forthe axle, and axle and journals being illustrated in plan.

Fig. 10 is a detail section similar to Fig. 9 through the axle journals.

Fig. 11 is a rear elevation of the truck connection taken in thedirection of the arrow II of Fig. l or 2, the tow bar being broken away.

Considering rst the details of the tamper machine properly, such beingdesignated by the assembly numeral I I in which I employ a machine orcarriage frame I2. 'I'he frame is illustrated as having side beams I3, arear end transverse beam I4, converging forward ends I5 of the sidebeams and parallel terminating ends I6, also of the side beams.Y A fronttransverse beam I1 connects the forward ends of the side beams I6. Sidebeams I3 with the converging portions I5 and the extension I6 mayconveniently be formed of channels with the webs I8 innermost and theflanges I9 projecting outwardly. The rear transverse beam I4 is also achannel connected by v welding or the like to the channels of the sidebeams vwith the web innermost. The forward transverse beam I1 is alsopreferably formed of a channel with the web 20 outermost and the flangesextending inwardly. A transverse brace bar 2| in the form of an anglejoins the side beams at the angle formed by the converging portions I5and the parallel portions I6. There is Yalso a transverse brace bar 22,also preferably formed of an angle adjacent the forward end ofVotherwise secured to the flanges of the forward transverse beam I1 andthis has a series of bolt holes 21. A vertical and rectangular spreaderplate 28 has a series of central bolt holes 29 ad- `jacent the top andis bolted to the transverse beam 22 by bolts 30 or the like. An anglebrace bar 3|, also preferably formed from an angle has its lower end 32with a flattened section 33, this flattened section being parallel tothe side beams I3 and is intended to Yride parallel to the bottom f ofthe trench. The lower and rear end 32 is secured by welding or the liketo the spreader blade 28 adjacent its center. A bolt 34 secures theupper end 35 sloping section of the brace bar to the depending angle 26.In this manner the spreader blade'may be adjusted up and down byshifting ythe bolts 36 and 34 to 'different' bolt holes.

The sheeps foot assembly 4D employs a drum designated by the assemblynumeral 4I.' This has an outer cylindrical drum section 42 and twoopposite circular heads 43 and 44 (note Fig. 9). These heads are insetfrom the edge of the drum forming a space 45 outside of the circularplates 43 and 44 and the side edges of the cylindrical drum portion 42.drical and extends through openings 41 in the ends 43 and 44 of the drumand is welded thereto by a filler weld 48 (note Fig. 10). The web I8 ofyeach of the side beams I3 preferably has a circular opening 49 toaccommodate a bearing block 56. This has a journal sleevey 5Icylindrical on the inside surface 52 and shaped on its outside surfaceto conform to the opening 49, it prefer-V ably being cylindrical on itsoutside surface. It is provided with a flange plate 53 on the outside,

this being preferably rectangular having a lowerv horizontal edge 54 andvertical edges 55. A rectangular spacing plate 56 is tted inside of theflange plate against the webs I 8 of the side beams I3 and this has anopening 51 to accommodate the sleeve 5I. I'he assembly is attached tothe webs I8 by bolts 58. There is also a washerlike wear plate 59 whichmay be circular and is preferably Welded tothe sides 44 of the drum andhas a circular opening 60 to accommodate the axle 46. It is to be notedthat the axle terminates as indicated at 6I (Fig. l0) slightly inside ofthe side beams I3, that is, inside of the webs of said beams. This is tofacilitate the assembly as the drum and axle may be aligned with the Anaxle 46 is preferably cylin-r f openings 49 in the webs of the sidebeams I3 and head or shoulder 61 shaped on the inside sur-V face with acylindrical curve to correspond with the drum 42 to which said head iswelded. On the ends of each leg there is a foot 68 which may beremovable by either threading in Yplace or by welding to the leg. Eachfoot may be conf sidered as having a heel 69 and forwardly pro-Yjecting. toe '10. The feet at the bottom are substantially rectangular.These are arranged preferably in rows longitudinally of the drum andalso are aligned in a circular manner on the periphery of the drum, suchbeing indicated in Figs. 1, 2, 4, 5, and 6. If desired the legsincluding the shoulder El and the feet Se may be cast as a single unitbut if the feet work in material subject to considerable wear, they maybe provided with a shallow socket 'li in which the ends of the legs 65extend and then they can have a light weld connecting each shoe to itsleg, such weld being readily melted for replacement of the Worn -feet.

The tow bar assembly 15 employsa rear tube orY pipe 'I6 (noteparticularly Figs. 6 and 7). This has a yoke 'I1 connected thereto, theyoke having a cross bar 18 and side arms "i9, these being illustrated asformed of channels with the Webs 80 innermost and the flanges 8lprojecting outwardly. Gusset plates 32 connect the cross bar 18 to thesides of the tube '56. A pair of pintle bolts 83 connect the side armsand the forward extension I6 of the side beams I3. It will be noted byreference to Fig. 5 that the side arms t outside of the extension |6.Telescopically mounted in the tube 16 there is a forward tube or pipe84, this having a series of diametrically opposite bolt openings 85through which is connected an attaching bolt 86, this bolt extendingthrough the pipe 'I6 at its forward end. The forward pipe 8d has aattened tongue 8l, such tongue being horizontal and a swivel towingcross member 88 is attached to this tongue. This swivel is illustratedas having a tube 89 with ears 90 welded thereto and the ears beingconnected by a vertical pivot bolt 9| to a tongue 81.

A suitable set up for towing the trench tamper may utilize a truckindicated by the numeral it@ (note Figs. 1, 2 and 11). .This truck has atube |0I connected thereto at the rear ends as by suspension straps |92(note Fig. 11). A projection tube |03 ts in the tube |0| extendingcompletely therethrough and being secured in place by a pin |04 throughboth the tube lili and |03. This tube |03 also extends through the tube89. There are a series of diametrically opposite perforations |05 in thetube |03 for insertion of centering pins I 06, which when insertedthrough these perforations engage the opposite ends of the tube 89. Inaddition a chain swivel |01 is secured to the outer projecting end ofthe tube |03 and a chain |08 leads diagonally from this to a securingpoint H35 on the truck. There is preferably employed a toggle leverassembly H0 or the equivalent for adjusting the length of the chain.This is for the purpose of readily detaching the chain which may beregulated in length by taking up on the links or extending the linkseither at the swivel or at the toggle lever connection.

In the illustrations a trench is indicated by the numeral H5. This hasopposite sides H6 and the bottom H1. It is presumed that at one side ofthe trench on which the truck travels that there is a clear driveway forthe truck. The dirt excavated from the trench is usually piled at theopposite side. In the procedure of filling the trench, a bull-dozer orthe like works along the side of the trench having the excavatedmaterial thereon and dumps this material into the trench, such dumpedmaterial being indicated by the irregular contour H8 (Fig. 2). Thetamper machine proper is lowered into the trench at one end in anysuitable manner or if desired the trench may have a grade or ramp at oneend so that the tamper part of themachine may be towed into the bottomof the trench. The tow bar is adjusted to the proper length and leadsupwardly at an angle as indicated in Figs. 2 and 6. The forward end ofthe carriage frame I2 is quite heavy so that the spreader plate 28contacts the irregularly dumped material H8 indicated in Figs. 2 and 4and spreads such material somewhat evenly over the bottom of the trench.If desired the forward end of the machine may be weighted so that thespread plate and the attened section 33 of the angle brace 3| runsapproximately on the top of the spread material. As such material isevenly spread the sheeps foot drum assembly rolls on this spreadmaterial, the legs and feet pene trating such material as indicated inFigs. 2 and 3; It will be noted that in the construction of the framethat this is approximately the width of the trench, the towingconnection to the truck restricts to a certain extent the lateralswivelling of the tow bar and when the truck is driven parallel to theside of the trench there is a straight and central longitudinal pull onthe tamper machine assembly ll. The forward projecting end having theside beams I5 and lI6 together with the yoke 'I9 restrict any sidewiseskewing of the machine frame and drum and thus assure that the framewill not dig into the side walls of the trench.

When the sheeps foot assembly has been operated from one end of thetrench to another or the desired length thereof, for instance in thedirection indicated in Fig. 2 over the freshly dumped material, theframe is inserted. This is done by tilting the forward end upwardlyafter unhitohing the truck and reversing the truck. Such action causesthe rear transverse beam I4 to contact the bottom of the trench, thatis, at the portion which has already been tamped and the machine iscompletely turned over to the position shown in Fig. 3. 'Ihe truck maythen be again connected and driven in a reverse direction back to thestarting point. In this reverse travel usually no fresh material isdumped in the trench but the material already dumped is thus given twoworkings or tampings. In such return movement the spreader plate 28 doesnot operate being in an elevated position, however should it be desiredto again spread the material in the bottom of the trench or to dumpfresh material therein, there may be two spreader assemblies such as 25,one extending below and the other above the frame of the machine, but asit is usually satisfactory to have only one assembly in the usualpractice of iilling trenches, only one is illustrated. After the returntrip of the tamper to its original position it is again reversed bybeing turned over on the rear transverse beam l@ and again assumes theposition shown in Fig. 2. As the tamper moves from thev end of its firsttravel in the trench to its starting point, a bull-dezer or the like maybe back filling into the trench an additional amount of loose material.In this manner the trench is gradually filled in and the material tampedin the periodical travel of the sheeps foot assembly from one end of atrench to the other or between designated portions of the long trench.

Various changes may be made in the details of the construction withoutdeparting from the spirit or scope of the invention as defined by theappended claims.

ritikll I claim:

1. In a trench tamper, a carriage frame, a drum having an axle, meansrotatably connecting the axle to the carriage frame, said drum havingtamping legs and feet, said frame having a forward extension beyond theperiphery ofthe drum and unbalancing the frame, a tow bar pivotallyconnected to said extension by a horizontal pivot whereby the to-w barmay form an upwardly inclined angle to the general plane of thecarriage, the weight of the forward extension being adapted tocounteract the upwardly inclined pull on the tow bar, a spreader plateadjustably connected to the forward extension on one side thereof andadapted to engage the soil for spreading in one direction of movement ofthe carriage and drum and on a reversed direction with the carriageturned upside down to be positioned above the bottom of the trench.

2. In a trench tamper, a carriage frame having a pair of opposite sidebeams, a rear end beam connecting said beams and a forward extension ofless width than that between the side beams to clear the walls of atrench and forming a connecting means at the forward end of the carriageframe, an axle, means forming a journal for the axle at the side beams,a drum having tamping legs and feet on the axle, a tow bar pivoted tothe forward extension by a horizontal pivot to permit a forwardinclination of the tow bar in reference to the side beams and forwardextension, a spreader assembly including a spreader plate adjustablymounted on the forward extension and depending therebelow in onedirection of travel of the carriage and drum, the said forward extensionand the spreader assembly being adapted to counteract an upward pull onthe tow bar to maintain the spreader plate in operative engagement withsoil at the bottom of the trench, the said rear end beam forming asupport for the drum when reversing the direction of the carriage, thesaid carriage when reversed having the spreader plate assemblyprojecting upwardly. 3. In a trench tamper as claimed in claim 2, therear end beam having a plurality of scraping fingers firmly attachedthereto and extending towards the drum and positioned to pass betweensuccessive tamping legs and feet during the rotation of the drum in thelongitudinal movement of the carriage.

4. In a method of trench tamping inwhich a carriage frame is providedwith a drum having tamping legs and feet and positioned in a trenchadjacent one end, moving the carriage with its top side upwardlylongitudinally of the trench to develop a rst tamping action on the soilat the bottom of the trench, secondly at the end of the first directionof travel reversing the carriage to turn the same upside down whileretaining the axis of the drum transverse to the trench, then moving thecarriage and drum in reverse direction to develop a second tampingaction on the soil at the bottom of the trench.

5. In a method of trench tamping in which a carriage frame having a drumwith tamping legs and feet is positioned at the bottom of the trench atone end thereof with the axis of the drum transverse to the trench,dumping filling material loosely in the trench, moving the carriage anddrum longitudinally of the trench and at the same time spreading theloosely dumped material in front of the drum whereby such loosely dumpedmaterial is tamped into the bottom of the trench, then while retainingthe axis of the drum transverse to the trench, reversing the position ofthe carriage to turn the same upside down, then moving the carriage withthe drum in reverse direction over the previously tamped section of thetrench to develop a further tamping action to additionally consolidatethe soil at the bottom of the trench.

6. In a trench tamper, a carriage frame having a drum rotatably mountedtherein, said drum having tamping legs with feet extending substantiallyradially from the periphery of the drum, said frame having a forwardextension, a tow bar pivotally connected to said extension by ahorizontal pivot whereby the tow bar may form an upwardly inclined angleto the general plane of the carriage for towing the drum in a trenchfrom a towing means on the ground level, the forward extension having anadjustable spreader plate positioned forwardly of the place of contactof the legs and feet with the bottom of the trench to spread earthdumped in the trench, Said forward extension and spreader plate beingpositioned relative to the axis of the drum to unbalance the carriageframe and counteract the upwardly inclined pull of the tow bar.

7. In a trench tamper, a carriage frame having side beams, an axlejournaled therein, a drum secured to the axle and having tamping legsand feet extending substantially radially therefrom, the side beamshaving a narrowed forward extension, a tow bar having a yoke pivotallyconnected by a horizontal pivot to said extension, the said side beamsbeing adapted to occupy a horizontal position and the tow bar anupwardly inclined position whereby the carriage may be towed lengthwisein a trench by a towing means travelling on the ground level and havinga connection to the upper end of the tow bar, the said forward extensionhaving a spreader assembly including a transverse spreader plate and anupwardly inclined brace bar extending from adjacent the spreader platetoI a connecting means at the forward end of the said extension, thespreader plate being adapted to spread earth dumped in the trench fortamping action by the legsand feet, said forward extension and spreaderplate being positioned relative to the axle of the drum to unbalance thecarriage frame and counteract the upwardly inclined pull of thetow bar.

FREDERICK W. WEBER.

